In a railway hopper car, it is desirable for the attendants to be able to tell at a glance whether one or all valve members on either side of the car are open or closed.
U.S. Pat. No. 3,730,360 discloses indicating flags which indicate the open or closed condition of discharge doors.
However, this patent does not teach an indicating system useful with an operating shaft effective to open and close valve members in the outlet.